High Wind Warning 7, NWS Juneau, AK

496 
WWAK77 PAJK 031136
NPWAJK

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE JUNEAU AK
336 AM AKDT SAT MAY 3 2014

AKZ025-031245-
/X.EXP.PAJK.HW.W.0007.000000T0000Z-140503T1200Z/
JUNEAU BOROUGH AND NORTHERN ADMIRALTY ISLAND-
INCLUDING THE CITY OF...JUNEAU
336 AM AKDT SAT MAY 3 2014

...HIGH WIND WARNING WILL EXPIRE AT 4 AM AKDT EARLY THIS
MORNING...

SEVERAL GUSTS OF 60 MPH OR MORE WERE RECORDED IN SOUTH DOUGLAS AND
DOWNTOWN JUNEAU OVERNIGHT. SOUTH DOUGLAS BOAT HARBOR TOPPED OUT AT
72 MPH AND THE FEDERAL BUILDING HIT 62 MPH. THESE WINDS HAVE SINCE
DROPPED OFF AND ARE NOT EXPECTED TO INCREASE AGAIN TODAY.

THIS WILL BE THE FINAL STATEMENT ON THIS EVENT.

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
420 PM AKDT FRI MAY 2 2014

.SHORT TERM...UPPER-LEVEL PATTERN CONTINUES TO BE DOMINATED BY A
CLOSED LOW OVER THE NERN PAC AND AN ANTICYCLONE CENTERED OVER
INTERIOR AK. IN ADDITION...MIDLEVEL DEFORMATION ZONE IS
POSITIONED OVER THE SRN PANHANDLE THIS AFTERNOON...WHILE A
PROGRESSIVE SHORTWAVE TROUGH WAS OBSERVED DROPPING S OVER NWRN
CANADA. BY SAT AFTERNOON...THE ANTICYCLONE OVER AK WILL DEVELOP
INTO A SW-NE ORIENTED RIDGE...THE CLOSED UPPER LOW WILL SHIFT E
TO A POSITION  S OF HAIDA GWAII...AND THE SHORTWAVE OVER NWRN
CANADA WILL CONTINUE TO MOVE S ACROSS BRITISH COLUMBIA.

 A STOUT YET SHALLOW INVERSION OBSERVED IN THE 12Z PAYA RAOB
MIXED OUT RAPIDLY BY LATE MORNING TODAY...RESULTING IN A RECORD
HIGH TEMPERATURE OF 73 /AS OF 22Z/ AT YAKUTAT. ELSEWHERE...WARM
TEMPERATURES IN THE MID 60S TO NEAR 70 WERE OBSERVED ACROSS THE
REMAINDER OF THE CWA. HOWEVER...AS THE CANADIAN TROUGH SLIDES SWD
INTO B.C. DURING SAT...850 MB TEMPERATURES ARE FORECAST TO COOL
BY ABOUT 5 DEG C OVER MUCH OF SE AK. THUS...EXPECT SAT AFTERNOON
HIGHS TO FALL BACK INTO THE LOW TO MID 60S WITH PLENTIFUL
SUNSHINE. IN ADDITION...MIXING WILL NOT BE AS STRONG TONIGHT
COMPARED TO THU NIGHT...SUCH THAT RADIATIONAL COOLING WILL FAVOR
FRI NIGHT LOWS IN THE LOW TO MID 30S FOR WIND SHELTERED
AREAS...TO AROUND 40 FOR AREAS EXPERIENCING SLIGHTLY STRONGER
SPEEDS. RH VALUES ARE ALSO FORECAST TO RANGE FROM 15-25 PERCENT
OVER THE SRN HALF OF THE CWA...WHICH WILL ELEVATE THE FIRE WEATHER
THREAT WHERE FUELS ARE LOCALLY DRY.

 TIGHT SURFACE PRESSURE GRADIENT OBSERVED THU NIGHT CONTINUES TO
GRADUALLY WEAKEN THIS AFTERNOON...THOUGH IT SHOULD REMAIN STRONG
ENOUGH THROUGH SAT MORNING FOR WIND SPEEDS TO HOVER AROUND SMALL
CRAFT VALUES FOR N-S ORIENTED INNER CHANNELS AS WELL AS CROSS
SOUND/ICY STRAIT. IN ADDITION...BY LATE SAT AFTERNOON...GRADIENT
MAY WEAKEN SUFFICIENTLY FOR THE OCCURRENCE OF LOCAL SEABREEZE
WINDS. FORECAST CONFIDENCE IS AVERAGE FOR WIND AND POPS/QPF...WITH
SLIGHT CHANCE OF SHOWERS OVER SRN AREAS EXITING THE REGION
TONIGHT. CONFIDENCE IS SLIGHTLY BELOW AVERAGE FOR TEMPERATURES AS
THE AIRMASS ABOVE THE SURFACE COOLS.

.LONG TERM...TWO UPPER LOWS...ONE OFFSHORE OF WASHINGTON STATE AND
THE OTHER SOUTH OF THE CENTRAL ALEUTIANS...ALONG WITH A RIDGE OVER
THE GULF FORMING A REX BLOCK THAT WILL ONLY ALLOW FOR VERY SLOW
PROGRESSION TO THE EAST. THUS THE DOMINATING FEATURE OVER THE
LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK WILL BE THE
LONGWAVE RIDGE. AS THE RIDGE AXIS ATTEMPTS TO MOVE EAST OF US
AROUND MIDWEEK, THINGS MAY BEGIN TO CHANGE. CONFIDENCE GREATER FOR
INCREASED CLOUD COVER THAN FOR RAIN CHANCES. BUT CLOUD COVER NOT
GREAT. MODELS TEND TO OVERESTIMATE THE SPEED OF THESE TRANSITIONS,
AND HAVE BEEN A LITTLE CONSERVATIVE AT ADDING CHANCES OF RAIN AT
THE END OF THE EXTENDED FORECAST.

ONE CHANGE TO INCORPORATE THIS ROUND WAS TO TILT THE GRADIENT MORE
ONSHORE WITH THE RIDGE. ALL THE MODELS SEEM TO BE INDICATING THIS.
MY CONCERN IS THAT IF ANY MARINE STRATUS FORMS, THIS COULD FLOW
COULD NOT ONLY LEAD IT COASTWARD BUT ALSO INVITE IT INSIDE ICY
STRAIT. BUT KIND OF USING THE 500 MB RIDGE AS GUIDE TO HOW FAR ANY
ADVANCES. AT ANY RATE, MORE MOISTURE COUPLED WITH ALREADY WARM
GROUND OVER THE MOUNTAINS COULD LEAD TO CUMULUS BUILDUPS OVER THE
WINDWARD SLOPES STARTING SUNDAY AND INTO MONDAY. THIS MAY DESERVE
PARTLY CLOUDY SKIES, BUT WENT OPTIMISTIC AS MOST OF US OUTSIDE
WILL SEE OUR SHADOWS. NEVERTHELESS MORE ONSHORE FLOW WILL DECREASE
TEMPERATURES TO MORE SEASONABLE LEVELS FOR SUNDAY AND MONDAY.
CLOUDS SHOULD DISSIPATE DURING THE NIGHT TIME HOURS AND ESPECIALLY
SATURDAY NIGHT, TEMPERATURES COULD SEE THE FREEZING POINT AGAIN
AWAY FROM THE WATER, WITH LIGHTER WINDS AND CLEARER SKIES. AGAIN
MORE ONSHORE FLOW AND MOISTURE IN THE BOUNDARY LAYER WILL HELP
KEEP THE TEMPERATURES A LITTLE WARMER SUNDAY NIGHT AND BEYOND.
ALSO IT SHOULD BE NOTED THAT MORE ONSHORE FLOW WILL ESPECIALLY
INCREASE RH VALUES IN THE AFTERNOON THUS REDUCING ANY FIRE RISK.
GRADIENTS WILL REALLY SLACKEN OVER THE INSIDE LATE SATURDAY NIGHT
AND REMAIN LIGHT THROUGH EARLY NEXT WEEK. ANY DAYTIME WIND FLOW
WILL BE STRICTLY DICTATED BY MESOSCALE PRESSURE/TEMPERATURE
DIFFERENCES.

INTERESTINGLY IN THE LONG-TERM, ECMWF SHOWING A RELATIVELY SHORT-
LIVED PERIOD OF WET LATE NEXT WEEK WITH AN EXITING LOW TO THE
SOUTHEAST. WHILE GFS KEEPS A LOW IN THE GULF LATE NEXT
WEEK...THEREFORE KEEPING A MORE PERSISTENT WET PERIOD. IT SHOULD
BE NOTED THAT MOST OF THE SOLUTIONS THAT GO THIS FAR HAVE A LOW
SOUTH OF JUNEAU, THEREFORE THE NORTHERN PANHANDLE WILL LIKELY BE
DRIER THAN THE SOUTHERN PORTION.

CONFIDENCE IN FORECAST GOOD FOR MID-RANGE...FALLING BY MID-WEEK.
USED ECMWF FOR MID-RANGE AND STOOD FIRM FOR LATER PERIODS.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ011>013-021-022-031-032-036-042-043-
     051-053.

&&

GARNER/JWA